Powders and Dispersions

Abstract

This powder includes: first particles having a first crystal composition; and second particles having a second crystal composition different from the first crystal composition, wherein each of the first crystal composition and the second crystal composition includes at least one selected from the group consisting of Ti2O3, γ-Ti3O5, and Ti4O7.

Description

[Technical Field]

[0001] The present disclosure relates to powders and dispersions containing particles having a specific low-order titanium oxide crystalline composition. [Background technology]

[0002] It is known that low-order titanium oxide (also called reduced titanium oxide) obtained by reducing titanium dioxide exhibits different colors depending on the ratio (crystal composition) of the constituent elements titanium and oxygen, and that black can be obtained by appropriately adjusting this ratio. Therefore, particles whose surfaces are composed of low-order titanium oxide can be used for various purposes as pigments, such as black pigments. For example, Patent Document 1 discloses cosmetics using a pigment that exhibits dichroism, in which the appearance color and interference color tone differ by forming a single layer of low-order titanium oxide on plate-like particles. Furthermore, Patent Document 2 discloses black titanium oxide powder prepared using CaH2 as a reducing agent for applications such as black pigments. Patent Document 3 discloses titanium oxynitride powder prepared by reacting titanium oxide with high-temperature ammonia gas. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-280607 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-214348 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-30842 Summary of the Invention [Problem to be solved by the invention]

[0004] Black pigments containing low-order titanium oxides can be generally referred to as black, but they can exhibit different shades of black, such as a black with a strong reddish tinge or a black with a strong blue tinge. Furthermore, depending on the shade, the same black may appear lighter or darker. For example, a light shade such as red or yellow may appear blacker than a dark shade such as blue or green, even if the black is the same. Therefore, it is preferable to have a high degree of freedom in adjusting the shade so that the shade of the black pigment can be selected depending on the application of the black pigment.

[0005] Therefore, one aspect of the present invention aims to provide a powder of low-order titanium oxide that can suitably adjust the color. [Means for solving the problem]

[0006] The present inventors have found that, as described above, by combining first particles and second particles having a crystal composition of Ti2O3, γ-Ti3O5, or Ti4O7 and different from each other, it is possible to suitably adjust the color tone. In particular, the L * a * b * L in color space * Regarding the value, surprisingly, the L * The value is the L of the first particle itself. * value and the second particle's own L * It was found that the value could be lower than that.

[0007] The present invention includes the following aspects. [1] A powder containing first particles having a first crystal composition and second particles having a second crystal composition different from the first crystal composition, wherein each of the first crystal composition and the second crystal composition contains at least one selected from the group consisting of Ti2O3, γ-Ti3O5, and Ti4O7. [2] The powder according to [1], wherein the first crystalline composition comprises Ti2O3 and the second crystalline composition comprises γ-Ti3O5. [3] The powder according to [1], wherein the first crystalline composition comprises Ti2O3 and the second crystalline composition comprises Ti4O7. [4] The powder according to [1], wherein the first crystalline composition comprises γ-Ti3O5 and the second crystalline composition comprises Ti4O7. [5] The powder according to any one of [1] to [4], further comprising third particles having a third crystal composition different from the first crystal composition and the second crystal composition and including at least one selected from the group consisting of Ti2O3, γ-Ti3O5, and Ti4O7. [6] A dispersion comprising the powder according to any one of [1] to [5] and a dispersion medium. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to provide a powder of low-order titanium oxide that can be suitably adjusted in color. [Brief explanation of the drawings]

[0009] [Figure 1] 1 shows the results of X-ray diffraction measurement of a low-order titanium oxide powder in an example. [Figure 2] 1 shows the results of X-ray diffraction measurement of a low-order titanium oxide powder in an example. DETAILED DESCRIPTION OF THE INVENTION

[0010] One embodiment of the present invention is a powder that includes first particles having a first crystalline composition and second particles having a second crystalline composition that is different from the first crystalline composition.

[0011] The first crystalline composition contains at least one selected from the group consisting of Ti2O3, γ-Ti3O5, and Ti4O7 (hereinafter, these are also collectively referred to as "low-order titanium oxides"). In one embodiment, the first crystalline composition may contain only one selected from the group consisting of Ti2O3, γ-Ti3O5, and Ti4O7. In another embodiment, the first crystalline composition may contain two or more selected from the group, and may contain Ti2O3 and γ-Ti3O5, or may contain γ-Ti3O5 and Ti4O7.

[0012] The second crystalline composition includes at least one selected from the group consisting of Ti2O3, γ-Ti3O5, and Ti4O7. In one embodiment, the second crystalline composition may include only one selected from the group consisting of Ti2O3, γ-Ti3O5, and Ti4O7. In another embodiment, the second crystalline composition may include two or more selected from the group, such as Ti2O3 and γ-Ti3O5, or γ-Ti3O5 and Ti4O7.

[0013] Note that the second crystal composition being different from the first crystal composition means that the second crystal composition does not completely match the first crystal composition. For example, if the first crystal composition is Ti2O3 and γ-Ti3O5 and the second crystal composition is γ-Ti3O5 and Ti4O7, the second crystal composition is different from the first crystal composition. In other words, the second crystal composition may have a common crystal structure with the first crystal composition (γ-Ti3O5 in the above example) as long as it does not completely match the first crystal composition.

[0014] That the first particles and second particles (and further the third particles described later) have the above-mentioned first crystalline composition and second crystalline composition (the third crystalline composition described later), respectively, can be confirmed by measuring the powder by X-ray diffraction (XRD) and observing only a diffraction peak attributable to at least one selected from the group consisting of Ti2O3, γ-Ti3O5, and Ti4O7.

[0015] Examples of combinations of the first crystal composition and the second crystal composition include the following combinations. (1) The first crystalline composition includes Ti2O3, and the second crystalline composition includes γ-Ti3O5. (2) The first crystalline composition includes Ti2O3 and the second crystalline composition includes Ti4O7. (3) The first crystalline composition includes γ-Ti3O5 and the second crystalline composition includes Ti4O7. In these combinations (1) to (3), each of the first crystalline composition and the second crystalline composition may contain only one of the above-mentioned low-order titanium oxides, or may further contain other low-order titanium oxides in addition to the above-mentioned low-order titanium oxides.

[0016] The low-order titanium oxide powder may further contain third particles having a third crystalline composition different from the first crystalline composition and the second crystalline composition, the third crystalline composition including at least one crystalline composition selected from the group consisting of Ti2O3, γ-Ti3O5, and Ti4O7.

[0017] The third crystalline composition includes at least one crystalline composition selected from the group consisting of Ti2O3, γ-Ti3O5, and Ti4O7. In one embodiment, the third crystalline composition may include only one crystalline composition selected from the group consisting of Ti2O3, γ-Ti3O5, and Ti4O7. In another embodiment, the third crystalline composition may include two or more crystalline compositions selected from the group, and may include Ti2O3 and γ-Ti3O5, or may include γ-Ti3O5 and Ti4O7.

[0018] Note that the third crystal composition being different from the first crystal composition and the second crystal composition means that the third crystal composition does not completely match either the first crystal composition or the second crystal composition. For example, if the first crystal composition is Ti2O3 and γ-Ti3O5, the second crystal composition is γ-Ti3O5 and Ti4O7, and the third crystal composition is γ-Ti3O5, the third crystal composition is different from the first crystal composition and the second crystal composition. In other words, the third crystal composition may have a crystal structure (γ-Ti3O5 in the above example) that is common to both the first crystal composition and the second crystal composition, as long as it does not completely match either the first crystal composition or the second crystal composition.

[0019] When the low-order titanium oxide powder further contains a third particle, for example, the first crystalline composition may contain Ti2O3, the second crystalline composition may contain γ-Ti3O5, and the third crystalline composition may contain Ti4O7. In this case, each of the first crystalline composition, the second crystalline composition, and the third crystalline composition may contain only one of the above low-order titanium oxides, or may further contain other low-order titanium oxides in addition to the above low-order titanium oxides.

[0020] The BET specific surface area of ​​each of the first particle, the second particle, and the third particle is 0.25 m 2 / g or more, 1m 2 / g or more, 2m 2 / g or more, 3m 2 / g or more, or 4m 2 / g or more, and 2 / g or less, 10m 2 / g or less, or 8m 2 / g or less. The BET specific surface area of ​​the low-order titanium oxide powder may also be within the above range. The BET specific surface area is measured by nitrogen gas adsorption using a specific surface area measuring device (e.g., Macsorb HM model-1201, manufactured by Mountech) at an equilibrium relative pressure of about 0.3, and is calculated as the average value of n=2. Degassing is performed using a nitrogen gas flow (atmospheric pressure) at 200°C for 10 minutes.

[0021] The amount of impurities in each of the first, second, and third particles (and further in the low-order titanium oxide powder) is preferably as small as possible. The Al content in each particle may preferably be 200 ppm by mass or less, 50 ppm by mass or less, or 20 ppm by mass or less. The B content in each particle may preferably be 50 ppm by mass or less, 30 ppm by mass or less, or 10 ppm by mass or less. The Ba content in each particle may preferably be 50 ppm by mass or less, 10 ppm by mass or less, or 5 ppm by mass or less. The Ca content in each particle may preferably be 100 ppm by mass or less, 50 ppm by mass or less, or 10 ppm by mass or less. The Cd content in each particle may preferably be 10 ppm by mass or less, 5 ppm by mass or less, or 2 ppm by mass or less. The Co content in each particle may preferably be 10 ppm by mass or less, 5 ppm by mass or less, or 2 ppm by mass or less. The Cr content in each particle may preferably be 100 ppm by mass or less, 10 ppm by mass or less, or 5 ppm by mass or less. The Cu content in each particle may preferably be 200 ppm by mass or less, 50 ppm by mass or less, or 10 ppm by mass or less. The Fe content in each particle may preferably be 200 ppm by mass or less, 50 ppm by mass or less, or 10 ppm by mass or less. The K content in each particle may preferably be 100 ppm by mass or less, 5 ppm by mass or less, or 1 ppm by mass or less. The Li content in each particle may preferably be 20 ppm by mass or less, 2 ppm by mass or less, or 0.5 ppm by mass or less.

[0022] The Mg content in each particle may preferably be 100 ppm by mass or less, 10 ppm by mass or less, or 1 ppm by mass or less. The Mn content in each particle may preferably be 10 ppm by mass or less, 5 ppm by mass or less, or 2 ppm by mass or less. The Mo content in each particle may preferably be 10 ppm by mass or less, 5 ppm by mass or less, or 2 ppm by mass or less. The Na content in each particle may preferably be 50 ppm by mass or less, 10 ppm by mass or less, 5 ppm by mass or less, or 2 ppm by mass or less. The Ni content in each particle may preferably be 50 ppm by mass or less, 20 ppm by mass or less, or 10 ppm by mass or less. The P content in each particle may preferably be 200 ppm by mass or less, 30 ppm by mass or less, 10 ppm by mass or less, or 5 ppm by mass or less. The Pb content in each particle may preferably be 50 ppm by mass or less, 5 ppm by mass or less, or 2 ppm by mass or less. The Sb content in each particle may preferably be 100 ppm by mass or less, 20 ppm by mass or less, 10 ppm by mass or less, or 2 ppm by mass or less. The Si content in each particle may preferably be 1000 ppm by mass or less, 100 ppm by mass or less, 30 ppm by mass or less, 20 ppm by mass or less, or 2 ppm by mass or less. The Zn content in each particle may preferably be 100 ppm by mass or less, 10 ppm by mass or less, or 2 ppm by mass or less. The Zr content in each particle may preferably be 100 ppm by mass or less, 20 ppm by mass or less, or 2 ppm by mass or less.

[0023] The total content of Na, K, and P in each particle may preferably be 2000 ppm by mass or less, 1000 ppm by mass or less, 500 ppm by mass or less, or 100 ppm by mass or less. The total content of Pb, Cd, and Cr in each particle may preferably be 200 ppm by mass or less, 100 ppm by mass or less, 50 ppm by mass or less, or 30 ppm by mass or less.

[0024] The amount of each impurity in the low-order titanium oxide powder may also be within the above range. The amount of impurities is measured using an Agilent 5110 ICP-OES (manufactured by Agilent Technologies, Inc.) by adding 1 mL each of HF and HCl to 0.1 g of a sample and subjecting the mixture to pressure acid decomposition (150°C, 4 hours).

[0025] The contents of the first particles, second particles, and third particles in the low-order titanium oxide powder are appropriately adjusted according to the desired color. The contents of the first particles, second particles, and third particles may be, for example, 5% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 95% by mass or more, or 95% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, or 5% by mass or less, based on the total amount of the low-order titanium oxide powder.

[0026] The low-order titanium oxide powder contains the above particles, and thus exhibits a black color with a predetermined chromaticity. * a * b * L in color space * The L value of the low-order titanium oxide powder is preferably 13.0 or less, more preferably 12.0 or less, and even more preferably 11.0 or less, and may be, for example, 4.0 or more, 5.0 or more, or 6.0 or more. * a * b * a in color space * The L value of the low-order titanium oxide powder is preferably −3.0 or more, more preferably −2.0 or more, and is preferably 8.0 or less, more preferably 6.0 or less, and even more preferably 4.0 or less. * a * b * b in color space * The value is preferably −8.0 or more, more preferably −6.0 or more, even more preferably −4.0 or more, and is preferably 1.0 or less, more preferably 0.0 or less.

[0027] L * a * b * L in color space * value, a * value and b * The value is measured using a colorimeter (e.g., ZE-2000 (manufactured by Nippon Denshoku Industries Co., Ltd.)). More specifically, after zeroing using a dark-field cylinder, standardization is performed using a standard white plate (X = 91.71, Y = 93.56, Z = 110.52). Next, approximately 3 g of low-order titanium oxide powder is placed in a 35φ × 15H round cell and measured.

[0028] The above-mentioned low-order titanium oxide powder can be obtained, for example, by mixing first particles and second particles (and, if necessary, third particles). The mixing can be either dry mixing or wet mixing, and since no solvent is used, there is no need to dry the solvent, so dry mixing is preferred from the viewpoint of reducing the production cost during mixing. Examples of mixing methods include mixing using an agate mortar, a grinder such as a ball mill or a vibration mill, or various mixers.

[0029] The above-mentioned low-order titanium oxide particles are suitably used as pigments (colored fillers) such as black pigments, etc. Such pigments (colored fillers) are suitably used as colorants in, for example, cosmetics, electronic components such as semiconductors, and coating materials such as paints and inks.

[0030] When the low-order titanium oxide powder is used for the above-mentioned purposes, the low-order titanium oxide powder is used by being dispersed in a dispersion medium, for example. That is, another embodiment of the present invention is a dispersion containing the low-order titanium oxide powder described above and a dispersion medium in which the low-order titanium oxide powder is dispersed.

[0031] The dispersion medium is appropriately selected according to the use of the dispersion, and may be, for example, water, alcohol, ketone, ester, resin, etc. Examples of the resin include epoxy resin, silicone resin, phenol resin, melamine resin, urea resin, unsaturated polyester, fluororesin, polyimide, polyamideimide, polyetherimide, polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, wholly aromatic polyester, polysulfone, liquid crystal polymer, polyethersulfone, polycarbonate, maleimide-modified resin, ABS (acrylonitrile-butadiene-styrene) resin, AAS (acrylonitrile-acrylic rubber-styrene) resin, AES (acrylonitrile-ethylene-propylene-diene rubber-styrene) resin, etc.

[0032] The content of the lower-order titanium oxide powder in the dispersion is appropriately selected according to the use of the dispersion, and may be, for example, 5% by mass or more and 90% by mass or less based on the total amount of the dispersion. The content of the dispersion medium in the dispersion is appropriately selected according to the use of the dispersion, and may be, for example, 10% by mass or more and 95% by mass or less based on the total amount of the dispersion.

Example

[0033] Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to the following examples.

[0034] <Preparation of Ti2O3 particles> Powder of TiO2 (product of Toho Titanium Co., Ltd., HT0514: purity 99.9%) and powder of TiH2 (product of Toho Tech Co., Ltd., TCH450: purity 99.8%) were mixed with an Ehrlich mixer (manufactured by Nippon Ehrlich Co., Ltd.) so that the molar ratio of TiO2 / TiH2 became 3.0 / 1 to obtain a mixture. This mixture was transferred to an alumina crucible and heated in an electric furnace (Fujidenpa Kogyo Co., Ltd., Himulti 10000) in an Ar atmosphere at a rate of 10°C / min up to 900°C for 12 hours. After heating, the obtained powder was pulverized in a mortar for 5 minutes to obtain particles (Ti2O3 particles) having a crystal composition containing only one kind of Ti2O3.

[0035] <Production of γ-Ti3O5 Particles> Powder of TiO2 (product of Toho Titanium Co., Ltd., HT0514: purity 99.9%) and powder of TiH2 (product of Toho Tech Co., Ltd., TCH450: purity 99.8%) were mixed with an Ehrlich mixer (manufactured by Nippon Ehrlich Co., Ltd.) so that the molar ratio of TiO2 / TiH2 became 4.8 / 1, and a mixture was obtained. This mixture was transferred to an alumina crucible and heated in an electric furnace (manufactured by Fuji Denpa Kogyo Co., Ltd., Himulti 10000) for 12 hours in an Ar atmosphere while heating up to 900 °C at 10 °C / min. After heating, the obtained powder was pulverized in a mortar for 5 minutes to obtain particles (γ-Ti3O5 particles) having a crystal composition containing only one kind of γ-Ti3O5.

[0036] <Production of Ti4O7 Particles> Powder of TiO2 (product of Toho Titanium Co., Ltd., HT's purity 99.9%) and powder of TiH2 (product of Toho Tech Co., Ltd., TCH450: purity 99.8%) were mixed with an Ehrlich mixer (manufactured by Nippon Ehrlich Co., Ltd.) so that the molar ratio of TiO2 / TiH2 became 7.0 / 1, and a mixture was obtained. This mixture was transferred to an alumina crucible and heated in an electric furnace (manufactured by Fuji Denpa Kogyo Co., Ltd., Himulti 10000) for 12 hours in an Ar atmosphere while heating up to 900 °C at 10 °C / min. After heating, the obtained powder was pulverized in a mortar for 5 minutes to obtain particles (Ti4O7 particles) having a crystal composition containing only one kind of Ti4O7. [[ID=II]]

[0037] [[ID=I4]]<Preparation of Lower Oxidation Titanium Powders> The Ti2O3 particles, γ-Ti3O5 particles and Ti4O7 particles obtained above were weighed and put into a plastic container so as to be in the ratios (mass%) shown in Table 1, and they were mixed for 3 minutes under the condition of an output of 60 G using a low-frequency resonance acoustic mixer LabRAMII (manufactured by Resodyn Acoustic Mixers, Inc.) to obtain lower oxidation titanium powders No. 1 to 13.

[0038] <X-ray Diffraction Measurement> Powder X-ray diffraction measurements were performed on each of the above-mentioned titanium lower oxides. Specifically, a sample horizontal multi-purpose X-ray diffractometer (manufactured by Rigaku Corporation, RINT-UltimaIV) was used to measure the diffraction pattern under the following measurement conditions. The obtained X-ray diffraction patterns are shown in Figs. 1 and 2. (Measurement conditions) X-ray source: Cu-Kα ray (λ = 1.54184 Å) Tube voltage: 40 kV, tube current: 40 mA Optical conditions during measurement: Divergence slit = 2 / 3° Scattering slit: 8 mm Receiving slit = 0.15 mm Position of diffraction peak = 2θ (diffraction angle) Scan speed: 4.0° (2θ) / min, continuous scan Measurement range: 2θ = 10° to 80°

[0039] <Measurement of chromaticity> For the above-mentioned Ti2O3 particles, γ-Ti3O5 particles, Ti4O7 particles and each titanium lower oxide powder, the chromaticity (L * a * b * value in the color space, L * value, a * value and b * value) was measured. More specifically, first, zero point correction was performed with a cylinder for dark field, and then standard adjustment was performed with a standard white plate (X = 91.71, Y = 93.56, Z = 110.52). Next, about 3 g of particles were placed in a round cell of 35φ × 15H, and the chromaticity was measured. The results are shown in Table 1.

[0040] <Measurement of BET specific surface area> The BET specific surface areas of the above-mentioned Ti2O3 particles, γ-Ti3O5 particles, Ti4O7 particles and each titanium lower oxide powder were measured by nitrogen gas adsorption at an equilibrium relative pressure of about 0.3 using a specific surface area measuring instrument (Macsorb HM model-1201, manufactured by Mountech), and the average value with n = ² was obtained. Degassing was performed at 200 °C for 10 minutes under a nitrogen gas flow (atmospheric pressure). The results are shown in Table 1.

[0041] [Table 1]

[0042] As can be seen from Table 1, by combining first particles and second particles (and even third particles) having a crystal composition of Ti2O3, γ-Ti3O5, or Ti4O7, and having different crystal compositions, the color can be suitably adjusted. * Regarding the value, surprisingly, the L * The value is the L of the first particle itself. * value and the second particle's own L * Specifically, for example, the L * The L value of γ-Ti3O5 particles is 11.2. * The L value of low-order titanium oxide powders 1 to 3, which are mixtures of these particles, is 10.8. * The L value was expected to be between 10.8 and 11.2, but surprisingly, the L values ​​of low-order titanium oxide powders 1 to 3 were * The value was lower than 10.8.

[0043] <Elemental analysis> The Ti2O3 particles, γ-Ti3O5 particles, Ti4O7 particles, and each low-order titanium oxide powder were subjected to elemental analysis using an Agilent 5110 ICP-OES (Agilent Technologies, Inc.). Specifically, 0.1 g of sample was weighed into a platinum crucible, and 1 ml each of HF and HCl was added. Pressure acid decomposition was performed at 150°C for 4 hours. The volume was then adjusted to 6 ml, and after confirming that there was no unnecessary residue, ICP optical emission spectroscopy was performed. The results are shown in Table 2. In Table 2, "ND" indicates that the value was below the lower limit of detection, and values ​​in parentheses indicate that the value was below the lower limit of quantitation. The lower limit of detection and the lower limit of quantitation are as follows: (detection limit) Li, Na, Mg, K and Ca: 0.5 ppm by mass P:5 mass ppm Elements other than those listed above: 2 ppm by mass (lower limit of quantification) Li, Na, Mg, K and Ca: 2 ppm by mass P: 10 mass ppm Elements other than those listed above: 5 ppm by mass

[0044] [Table 2]

Claims

1. first particles having a first crystal composition; and second particles having a second crystal composition different from the first crystal composition, Each of the first crystal composition and the second crystal composition is Ti ２ O ３ , γ-Ti ３ O ５ and Ti ４ O ７ A powder comprising at least one selected from the group consisting of:

2. The first crystal composition is Ti ２ O ３ and the second crystal composition is γ-Ti. ３ O ５ 2. The powder of claim 1 , comprising:

3. The first crystal composition is Ti ２ O ３ and the second crystal composition comprises Ti ４ O ７ 2. The powder of claim 1 comprising:

4. The first crystal composition is γ-Ti ３ O ５ and the second crystal composition comprises Ti ４ O ７ 2. The powder of claim 1 , comprising:

5. The powder described in claim 1, wherein a combination of the first crystal composition and the second crystal composition is any of the following combinations. (1) The first crystal composition contains only Ti 2 O 3 , and the second crystal composition contains only γ-Ti 3 O 5 . (2) The first crystal composition includes only Ti 2 O 3 , and the second crystal composition includes only Ti 4 O 7 . (3) The first crystal composition contains only γ-Ti 3 O 5 , and the second crystal composition contains only Ti 4 O 7 .

6. The first crystal composition and the second crystal composition are different, and Ti ２ O ３ , γ-Ti ３ O ５ and Ti ４ O ７ The powder according to any one of claims 1 to 5, further comprising third particles having a third crystal composition comprising at least one selected from the group consisting of:

7. A dispersion comprising the powder according to any one of claims 1 to 5 and a dispersion medium.

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